Chair-iron.



PATENTED JAN.14, 190s. P. 'CHIOHBSTER. CHAIR IRON.

APPLICATION FILED D30. 31, 1906.

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PATENTED JAN. 14, 1908. F. GHIOHESTER.

CHAIR IRON.

APPLIOATION FILED DEC. 31, 1906.

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FRANKLIN OHIOHESTER, OF POUGHKEEPSIE, NEW YORK.

CHAIR-IRON.

Specification of Letters Patent.

Patented Jan. 14, 1908.

2. Application filed December 31,1906. Serial No. 350239.

T 0 all whom it may concern:

Be it known that I, FRANKLIN Cni- CHESTER, a citizen of the United States of America, residing at Poughkeepsie, Dutchess county, New York, have invented certain newand useful Improvements in' Chair-Irons, of which the following is a specification.

My invention relates to looks for chair .backs, whereby the back may be set and locked in any one of a series of positions, and it consists in the arrangement of the locking devices whereby with wide range of position, great strength with comparatively light weight, is secured, rendering it possible to construct the lock of a class of metal entirely different from that required for other forms.

Figure 1 is a view in perspective of the lock assembled and ready for attachment to a chair back. Fig. 2 is an elevation of one side of the casing with the other parts removed therefrom. Fig. 3 is a sectional view of a part of a chair back showing the lock located therein, one side of the lock casing being removed to more clearly exhibit the interior. Fig. 4 is a vertical sectional view of a portion of a chair back equipped with such a lock, the parts being in the positions they occupy when unlocked to permit the swinging of the back on its pivot. Fig. 5 is a vertical sectional view of a chair back, equipped with such a lock, in the position occupied by the various parts when the back is set at an angle, the interior parts of the lock being shown in dotted lines. Fig. 6 is an end elevation of the lock in its case, showing the dovetail form of the tenon member of the device by which the chair back and its attached lock are connected. to the chair seat.

This chair iron or lock is intended for a class of chairs, known as typewriters chairs, sewing machine chairs, etc., in which different occupants (or even the same occupant at different times) desire that the angle between the back and the seat shall be varied. To meet this want many devices have been constructed. Some have been made of steel, as strength and shock-resisting qualities are requisite.

To provide the necessary strength and shock resisting qualities in a lock of difierent material, I have devised the arrangement shown herein, in which a latch pivoted and arranged as hereinafter described is supplemented by an operating lever, so formed, placed and connected that it'cooperates with the latch in resisting the shocks and strains incident to use, permits the employment of metal of less tensile strength and at the same time requires less outer movement of the thumb piece than was required in my previous lock.

6 is the carrying art of the frame. It consists of a metal p ate substantially equal in width to the back intended to hold it, notched as at 34 to receive the engaging tang of the other part of the frame and provided with flanges 7, at each side of the outer side edges and the interior side edge at the rear. This plate also carries pivots 8, 9 and 10, post 11, and bearing piece 12, pivots 8 and 10 being tapped and threaded.

14 is the engaging device intended to fit with a corresponding one on the seat and thus secure the back and seat together. As here shown it is a tapered dovetail tenon, adapted to engage a dovetail mortise on the seat, but tenon and mortise might be reversed as to their locations or other forms might be used. This tenon is provided with an extension, 15, which projects in between the sides of the case and is therein secured on pivot, 8. At the lower end this tenon carries a rack, 1 6, having a series of teeth on its upper face and a stop, 17, at the end, which stop engages a second stop, 18, on the casing, when the rack is fully extended, and prevents its being withdrawn entirely without the case. On pivot, 10, I suspend the latch, 19, provided with a tooth, 20 and an inclined slot, 21. Then on pivot 9 I mount an operating lever, 22, with a thumb piece, 23 and a projection, 24, which enters and moves in slot 21. The lower side of that slot is referably serrated that the engagement of projection 24 in a depression of such serrations may aid the engagement of the tooth, 20, and the'rack, 16, in firmly holding the parts in place.

A spring, 25, mounted on post 11 bearing against piece 12 on one side and the operating lever 22 on the other, through that lever, holds its connected latch in a position of engagement with rack 16. r

26 is the cover or companion plate of the lock casing, having flanges 27, and 28 and locking tang 29 as well as a ertures 30 and 32 for the screws which hol the casing together and retain the parts in place and 31, to form a bearing for the pivot of the lever, 22.

When the occupant of the chair whose back is equipped with such a lock desires to alter its angle of inclination toward or from the seat, he or she lifts thumb piece 23, or rather presses it inward. The result of such action is shown in Fig. 4. The spring, 25, is compressed, the lower arm of that lever, carrying projection 24, is swung toward the back of the case, and in such movement the projection 24 acts as a cam' and bearing against the upper inclined face of the wall of slot 21, raises latch 19 and its tooth 20 from its engagement with rack 16, and the back is unlocked. The occupant swings the back, on its pivot 8, to the desired position, for instance that of Fig. 5, and then releases the thumbpiece. A spring, 25, returns the lever 22 to its normal position, carrying latch 19 downward till its tooth 20 engages a new notch in rack 16, and the back is locked in its new position, the seating of projection 24 in a new serration in the wall of slot 21, aiding to that end. It will be noted that when the back has taken this new position, the tooth 20 of latch 19, the projection 24, and the pivot 9 of lever 22, are nearly in one vertical line and the lever extends in substantially a straight line from its pivot to its engagement with the latch at a point in a straight line with the tooth 20, whereby that tooth is always strongly supported and the liability of fracturing the latch between its tooth and its pivot is almost if not quite entirely removed. If 'then a back with this lock be removed from a chair and forcibly replaced, or if the occupant lean back quickly and forcibly, or the chair be overturned, nevertheless the parts are so arranged as to receive and endure the shock without fracture, to a very much greater extent than any irons of equal weight but differently formed and combined.

What I claim as my invention and desire to secure by Letters Patent is:

1. A chair lock composed of a casing, a supporting member pivoted thereto and provided with means for securing it to a chair seat, the said means consisting of a portion projecting beyond the casing and adapted to engage a second and complemental member on the chair seat, a rack secured to said supporting member and projecting within said casing, a latch pivoted to said casing near one side, extending toward the other side and provided with a tooth adapted, when lowered, to engage the said rack, and an operating lever, pivoted in said casing, and provided with an engaging device engaging the said latch, within said casing, and a thumb piece extending beyond the said casing, all substantially as set forth.

2. A chair lock composed of acasing, a supporting member pivoted thereto and provided with means for securing it to a chair seat, the said means consisting of a portion projecting beyond the casing and adapted to engage a second and complemental member on the chair seat, a rack secured to said supporting member and projecting within said casing, a latch pivoted to said casing near one side, extending toward the other side and provided with a tooth adapted, when lowered, to engage the said rack, an operating lever, pivoted in said casing, and provided with an engaging device engaging the said latch within said casing and a thumb piece extending beyond the said casing, and a spring engaging said operating lever, all substantially as set forth.

3. A chair lock composed of a casing, a supporting member pivoted thereto and pro. vided with means for securing it to a chair seat, the said means consisting of a portion projecting beyond the casing and adapted to engage a second and complemental member on the chair seat, a rack secured to said supporting member and projecting within said casing, a latch pivoted to said casing near one side, extending toward the other side and provided with a tooth adapted, when lowered, to engage the said rack, and an operating lever, pivoted in said casing and provided. with an engaging device engaging the said latch, vithin said casing, and a thumb piece extending beyond the said casing; the length of the operating lever from its pivot to that part which engages n ith the latch and that of the latch. from its pivot to the part which en.- gages with the operating lever, when the latch is down, being so proportioned and arranged that, the engaging device of the lever will engage the latch, when it is down, at a point which is substantially in a line drawn from the lever pivot to the latch tooth and at least as far from the latch pivot as that point on said line which is nearest to the latch pivot, as and for the purpose set forth.

1. A chair lock composed of a casing, a supporting member pivoted thereto and provided with means for securing it to a chair seat, the said means consisting of a portion projecting beyond the casing and adapted to engage a second and complemental member on the chair seat, a rack secured to said supporting member and projecting within said casing, a latch pivoted to said casing near one side, extending toward the other side and provided with a slot and a tooth adapted, when lowered, to engage the said rack, and an operating lever, pivoted in said casing, and provided with an engaging deviceextending into the latch slot, engaging the said latch, within said casing, and a thumb piece extending beyond the said casing, all substantially as set forth.

5. A chair lock composed of a casing, a supporting member pivoted thereto and provided with means for being secured to a chair seat, said means consisting of an extension in the form of one portion of a mortise and tenon joint, adapted to engage a second portion of a mortise and tenon joint secured to a chair seat, a rack secured to said supporting member, a latch pivoted to the casing near one side, extending well toward the other side and provided with a tooth engaging the rack, and an operating lever having a thumb piece, pivoted in said casing and provided with. an engaging device engaging said latch near the end furthest from the pivot, all combined substantially as set forth.

6. A chair lock composed of a casing, a supporting member pivoted thereto, and provided with means for being secured to a chair seat, said means consisting of an extension in the form of one portion of a mortise and tenon oint, adapted to engage a second portion of a mortise and tenon joint secured to a chair seat, a rack secured to said supporting member, a latch pivoted to the casing near one side, extending well toward the other side and provided with a slot and a tooth engaging the rack, and an operating lever having a thumb piece,pivoted in said casing and provided vith an engaging device extending into the latch slot and engaging said latch near the end furthest from the pivot, all combined substantially as set forth.

7. A chair lock composed of a casing, a supporting member pivoted thereto near the top and provided with means for being secured to a chair seat, said means consisting of an extension in the form of one portion of a mortise and tenon joint, adapted to engage a second portion of a mortise and tenon joint secured to a chair seat, a rack secured to said supporting member, a latch pivoted to the casing near one side, extending well toward the other side and provided with a tooth engaging the rack, and an operating lever having a thumb piece, pivoted in said casing and provided nith an engaging device engaging said latch near the end furthest from the pivot, all combined substantially as set forth.

8. A chair lock composed of a casing, a supporting member pivoted thereto and provid ed with means for being secured to a chair seat, said means consisting of an extension in the form of one portion of a mortise and tenon joint, adapted to engage a second portion of a mortise and tenon joint secured to a chair seat, a rack secured to said supporting member, a latch pivoted to the casing near one side, extending Well toward the other side and provided with a slot whose lower wall is serrated and a tooth engaging the rack, and an operating lever having a thumb piece, pivoted in said casing and provided with an engaging device extending into the latch slot and engaging said latch near the end furthest from the pivot, all combined substantially as set forth.

9. A chair lock composed of a casing, a supporting member pivoted thereto and provided with means for being secured to a chair seat, said means consisting of an extension in the form of one portion of a mortise and tenon joint, adapted to engage a second portion of a mortise and tenon joint secured to a chair seat, a rack secured to said supporting member, a latch pivoted to the casing near one side, extending well toward the other side and provided with a tooth engaging the rack, an operating lever having a thumb piece, pivoted in said casing and provided with an engaging device engaging said latch near the end furthest from the pivot, and a spring engaging said operating lever, all combined substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses, this 22 day of December, 1906.

FRANKLIN CHICHESTER.

Witnesses:

FRANK G. CUNLEY, WM. HANBERMERTEL. 

